Daern became a devoted companion of Flaergon of Glister, a priest of Ilmater who dedicated himself to assisting miners and caravan-workers in the frozen north of the Moonsea lands. Flaergon was also the bearer of the Tome of Torment, one of holiest books of the Ilmatari faith. After Flaergon died of a fall in a chasm near Whitehorn in the Year of the Claw, 1299 DR, Daern took the Tome of Torment across all of Faerûn back to the House of the Broken God temple in Keltar, Calimshan.
Daern presented the Tome to the High Mistress of Worthy Suffering, Althea the Abased. Daern's devotion so moved Althea that she named him an honorary Brother of the temple. Daern became Althea's personal bodyguard, but his duties consisted largely of carrying the frail, crippled priestess around.
Althea the Abased finally passed on in the Year of the Gate, 1341 DR, and Daern mourned her passing. He was given a new role as Guardian of the Tome, defending the artifact he'd once traveled so far to deliver. Unfortunately, within a year, Daern was murdered one night by a semi-monstrous man—Althea's predecessor, Bloirt Waelarn—who stole the Tome and escaped.
The Ilmatari remembered Daern and his long journey in the saying "long and strong as Daern's devotion".